It’s the last week of the NFL preseason and the San Francisco 49ers are gearing up to take on the visiting Los Angeles Chargers on Thursday night.

While sightings of starting players will be limited at best, the fourth and final preseason game will help decide the last few roster spots still up for grabs. Here are five things to pay attention to when the Chargers come to town.

Garnett is back in the running for starting right guard

The competition for the starting job at right guard for the 49ers has been a lingering storyline for the majority of training camp.

Former first round pick Joshua Garnett was the tentative starter at the beginning of camp until a knee contusion forced him to miss nearly two weeks.

While absent, Garnett relinquished the starting job to Mike Person, who started in the team’s dress rehearsal in Indianapolis last Saturday.

“I would say it’s his job to lose right now or however you want to say it,” said head coach Kyle Shanahan. “Josh [Garnett] could beat him out. But, Person has been the most consistent since day one and he’s had a real good camp. We’ll see what happens these last few days.”

According to the current depth chart released by the 49ers, though, Garnett has been granted the starting job against Los Angeles. Likely, Garnett’s strong play against the Colts had a lot to do with the decision.

“Josh definitely helped himself out last week,” Shanahan said Tuesday. “I’m glad we’ve got another game to watch it. We had a good practice today where we’ll still get to evaluate when we get in there. I look forward to watching him on Thursday.”

While Shanahan and Co. have yet to name a starter for Week 1, how Garnett plays on Thursday will likely affect which way they decide to go.

Who will round out the 49ers receiving corps?

There’s no doubt that the 49ers have a plethora of talent within their wide receiving unit.

Unfortunately for San Francisco, though, there won’t be enough room to keep everyone on the 53-man roster come Saturday at 1 p.m., when NFL teams are required to make final cuts.

So far, the locks to make the team are as follows: Pierre Garçon, Marquise Goodwin, Trent Taylor and rookie Dante Pettis.

This leaves Victor Bolden Jr., Kendrick Bourne, Aaron Burbridge, Steven Dunbar Jr., rookie Richie James Jr. and Aldric Robinson on the bubble with a projected maximum of two additional wide receivers to round out the group.

The frontrunners of the group are likely Bourne and James Jr., who have both played well in practice and in preseason games. Bolden isn’t far behind either, as the Oregon State product has had his moments this preseason as well.

James has been the most productive of the bunch, racking up 112 yards and one touchdown in three games, making him a hard cut, while Bourne has only accumulated 58 yards and no scores. What makes Bourne desirable, though, is the fact that he has an entire year of experience in Shanahan’s system.

In Bolden’s case, four receptions for 86 yards in two games is nothing to scoff at but a four-game suspension for PED use may be too much for the 49ers to look past.

The 49ers may debut another new running back

San Francisco signed former Humboldt State running back Ja’Quan Gardner on Tuesday afternoon.

Gardner is now the second running back the 49ers have inked in the last two weeks after starting halfback Jerick McKinnon and backup Matt Breida each suffered injuries in Week 1 of the preseason.

While he’s only had two days to prepare, Shanahan will likely want to see what Gardner has to offer Thursday against the Chargers.

In four seasons as Humboldt, Gardner rushed for 5,495 yards and scored 72 touchdowns, including 25 TDs in 2015.

Standing 5-foot-6 and weighing 191 pounds, Gardner is not the prototypical NFL running back. That, coupled with a 4.57-second 40-yard dash would explain his undrafted free agent status before signing in San Francisco.

The 49ers invited Gardner to their rookie tryout camp earlier in the offseason but did not extend a training camp invitation in July.

“He did a good job in our rookie tryout camp,” said Shanahan. “We always liked his college tape, and he ran well while he was here. We’re down some guys and we wanted to make sure we got another guy in here and he was a guy that we had on our short list since he was here in the tryout camp.”

Will Joe Williams play despite injury?

Thursday will be second-year back Joe Williams’s last chance to convince the 49ers coaching staff that he deserves a spot on the final 53-man roster.

The only problem is that he might not be able to suit up thanks to a fractured rib sustained two weeks ago versus Houston. According to Shanahan, though, he isn’t ruled out just yet.

“Joe didn’t practice [Tuesday],” said Shanahan. “But we’ll see how he is tomorrow.”

For Williams, a lackluster preseason has pushed him to the back of the depth chart. On 19 carries, Williams has only been able to gain 45 yards, averaging 2.3 yards per attempt.

Williams will likely be a game-time decision Thursday night as his future with the franchise hangs in the balance.

Who will emerge as the third tight end?

While George Kittle (shoulder) and Garrett Celek are essentially locks for the final 53, the 49ers have a decision to make for the third, and final, tight end spot on the roster.

Last week, Louisville product Cole Hikutini would have solidified his position, were it not for a dropped touchdown pass from Jimmy Garoppolo against Indianapolis.

Cole Wick is the man on Hikutini’s heels after taking reps with the first team offense in Houston. Wick is easily the better blocker in the run game, as Hikutini offers more versatility on the passing game.

A strong game from either could land them a job in Week 1 of the regular season.